This same thing happened to me a couple of months ago. I got hit on the left buttock by a half-empty water bottle. The redneck who threw it leaned out the passenger window and laughed as they passed me. Then within 500 yards, they came to a red light. He withdrew into the cage. I stopped a couple of car lengths back and studied the license plate. There's another red light a block later, and I caught up to them again there and stared them down like a Neaderthal. At least, I managed to keep my mouth shut.

I called the police with license plate number, vehicle description and description of both driver and passenger. The officer, after promising to keep an eye out for this type of behavior on his regular patrol (as if he's going to witness this happening), asked, "What do you expect me to do?" I said, "Could someone at least knock on their door and tell them not to do that?" He said, "Sure, we can do that." Honestly, I think that's the best you can hope for in a case like this. Sure, you know as a cyclist that an incident like this could kill you in the worst case scenario. There was a case here recently where a man in an SUV intentionally ran down a cyclist after an argument in a parking lot. He was convicted of third degree assault but found not guilty of first and second degree assault. The local cycling community, of course, was ready to string him up from the nearest tree.